π-Delocalization in the vicinal lone pairs of hydrazines: Structure and electronic effects in derivatives of 9-aminocarbazole

• The molecular and electronic structures of carbazoles. • The bonding is markedly substituent dependent. A series of four substituted carbazoles with N-N bonds have been prepared, characterized, and structurally determined by single crystal X-ray diffraction. These include derivatives with donating amino, NNH 2 , electron withdrawing mono-and bisacetyl, NNHC(O)Me and NN[C(O)Me] 2 , and conjugating Shiff base derivatives from the condensation of 9-aminocarbazole with arylaldehydes. The electronic structure and optimized gas phase structures of all four have been determined with density functional theory, B3LYP, and triple zeta basis sets either 6-311++g** or cc-pvtz. Together these experimental and theoretical results allow for the contrast of all four predominant N-N bonds in hydrazine derivatives.